// 数组去重
const removeDuplication = (array) => {
  const result = []

  array.forEach(val => {
    if (result.indexOf(val) === -1) result.push(val)
  })

  return result
}

const arr = [1,2,3,4,5,6,7,2,4,7,8,9,34,76,34,7,4545,78,3,34]
console.log(removeDuplication(arr))

let a = 100;
function test() {
  console.log(a);
  a = 10;
  console.log(a);
}
test();
console.log(a);
